The world of music is a complicated one. I would not suggest using any sort of contract that was not drafted directly by a competent entertainment lawyer. But if you insist on hacking up your own, the top things your contract needs to address are:
* Recording rights granted on the composition (eg, number of masters)
* Royalty rate for the mechanical distribution of the work
* Ownership of copyright and derivative works
* Synchronization rights granted on the work
* Performance rights granted on the work
* Your right to audit records in order to determine royalties
Remember, you can use a very fundamental contract to license your work. But if you ever want to make any real money in the music business, the users who can generate that kind of income for you will never license your music using a fundamental contract!